I get an big error when im done with a course on a subsite

I get an big error when im done with a course on a subsite:

https://demo.simplylearn.no/mine-kurs/oppsetting-av-din-laeringsplattform/course-completion/
Oops! That page can’t be found.
It looks like nothing was found at this location. Maybe try one of the links below or a search?

I have found this: https://premium.wpmudev.org/forums/topic/why-are-all-my-coursepress-virtual-pages-returning-oops-that-page-cant-be-found

But this is an multi site so Permalinks is not an option on a multisite.

But the problem is global.